添加片段时,会出现"错误的第二个参数类型"错误

Question

我检查了类似的帖子,他们的解决方案似乎不起作用.我(显然)对此很陌生,所以我可能只是缺乏技巧.

我收到错误:

"找到错误的第二个参数类型:'mycompany.fragment_test ... required:'android.support.v4.app.Fragment

replace(int,android.support.v4.ap.Fragment)to(int,mycompany.fragment_test ...)'

import android.support.v4.app.FragmentActivity;
import android.support.v4.app.FragmentTransaction;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.Fragment;
import android.os.Bundle;


public class MainActivity extends FragmentActivity {

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

    if (findViewById(R.id.fragment_container) != null) {
        if (savedInstanceState != null) {
            return;
        }

        FragmentManager fm = getSupportFragmentManager();
        FragmentTransaction ft = fm.beginTransaction();

        Menu_Fragment fragment = new Menu_Fragment();
        fragment.setArguments(getIntent().getExtras());



        ft.replace(R.id.fragment_container, fragment); //This is the line with the issue
        ft.commit();

    }

  }
}

Answer 1

Menu_Fragment不是继承自android.support.v4.app.Fragment.据推测,它是继承自android.app.Fragment.

有两个片段实现:本机(例如android.app.Fragment)和后端(例如android.support.v4.app.Fragment).你需要保持一致.你的活动是a FragmentActivity,它是backport的一部分,所以你需要你的片段继承android.support.v4.app.Fragment.